This invention relates to the prevention of heat loss through closed window and patio door openings of residential buildings, and more particularly concerns a rectangular multi-paneled assembly adapted to be inserted into the enclosure frames of such windows and doors.
The prior art includes many forms of coverings adapted for attachment to an existing primary window frame or sliding-type patio door, preferably from the interior side of the window or door. Among the disclosed types of coverings are auxiliary windows comprised of thin sheet plastic glazing held tautly by frames adapted to fit within a primary window frame. Typical examples of such auxiliary windows are disclosed in U.S. Pat. No. 4,193,235 to Cucchiara and U.S. Pat. No. 4,068,428 to Peterson. Such devices, however, utilize frame structures of considerable complexity and expense, and which are not easily installed into and removed from the primary window frame. Some of such devices require that modifications be made in the primary window or frame to facilitate installation.
The auxiliary window coverings are generally intended primarily to act in association with the primary window to create a stagnant air space which serves as a barrier to heat transfer through the primary window. The auxiliary window covering generally does not, in and of itself, provide thermal insulation. Furthermore, unless the auxiliary window forms a tight seal with the primary window, the insulative effect of the stagnant air space will be lost or greatly diminished.
It is accordingly an object of the present invention to provide a thermally insulative covering fabricated of thin sheet plastic material.
It is another object of this invention to provide a covering as in the foregoing object having a frame which facilitates easy association and dis-association with the interior surface of a window or door without requisite modification thereof.
It is a further object of the present invention to provide a covering of the aforesaid nature which causes a stagnant air space to be formed adjacent the interior surface of a window or door.
It is still another object of this invention to provide a covering of the aforesaid nature of rugged and durable construction amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.